(1). Field of the Invention
The present invention relates to an engine management system which is suitable for appropriately and precisely performing maintenance, failure management, running-in process and other management of outboard motors, multi-purpose engines, engines for jet-skis and other various engines.
(2). Description of the Prior Art
Conventional outboard motors have had a warning system of informing the user of an anomaly, mentioned below, when it occurred, by a warning buzzer, a warning lamp (LEDs, etc.) or by lowering the number of engine revolutions, so as to promote the user to manage it (the dealer's checkup, replacement of consumables, and/or supplying of oils). The examples of anomalies include, overrev, oil pressure lowering, reduction of oil (for two-cycle oil), oil flow (from clogging in the 2-cycle oil piping), overheat, battery's undervoltage, and so on.
In this conventional art, the system is adapted to promote the user to take a quick action by lowering the number of engine revolutions or any other way, but, as the product's nature of outboard motors, the engine is enabled to continue running at a low speed (high-speed running is prohibited by revolution regulation), in case of emergency (such as being drifted).
However, in some cases, continuation of operating the engine during overheat warning or oil flow warning may cause damage to the engine depending upon the degree of the overheat (degree of reduction of the amount of cooling water) and/or the time of running in the state. When an engine which was used to sail for emergency under warning conditions, not limited only to overheat or oil flow warning, needs to be checked up, or when a defective engine is checked up, if information about under what kind of warnings the engine was used and in what conditions (time, temperature, etc.) it was used to sail under the warning state is known, it is possible to perform efficient and exact maintenance of it. However, in the conventional configurations, only the alarms of warnings (by lamp indication, buzzing sound, lowering the number of engine revolutions) was provided as stated above.
An outboard motor (for jet ski, and multi-purpose engines etc.), differing from motorcycle or four-wheel vehicles (because it has no wheels), has no means for detecting absolute distance of movement. Though it has a speed meter which is operated making use of water pressure during forward movement, this speed meter produces fluctuations in measurement, depending upon the pressure detecting position, the hull shape, forward/backward movement and turning and other factors, so that it cannot measure the total distance of movement. Therefore, in general, an hour meter is used in place.
However, the information obtained from an hour meter depends upon user's utility or how the user used the vehicle. For example, use of the hour meter only gives the information of time, so the same result will be obtained when the vehicle sails for one hour at 1000 rpm and when it sails for one hour at 6000 rpm, despite the fact that the distance of movement and exhaustion and deterioration of parts and oils differ manifold.
Because of the above fact that the time measurement cannot provide exact information and because the conventional hour meter is costly and other reasons, outboard motors mostly had no hour meter and hence it was difficult to maintain them, needing high cost for exact management.
Moreover, outboard motors, from their product's nature, are driven continuously under high load at high number of engine revolutions, more frequently compared to the engines for two or four-wheel vehicles having a transmission device. Despite such use conditions, it was difficult to grasp the exact time, exact distance of sailing and perform exact maintenance from the reasons described above, so that it was impossible to manage and perform the running-in process in a good enough manner.